{"apiVersion":"1.0","identifier":"CVE-2026-53586","description":"libgit2 is a portable C implementation of the Git core methods provided as a linkable library with a solid API, allowing to build Git functionality into your application. Prior to 1.8.6 and 1.9.5, the built-in HTTP transport in src/libgit2/transports/http.c follows an offsite initial redirect, and handle_remote_auth and handle_auth pass transport->owner->url instead of transport->server.url to the credential callback when the redirected host returns 401 Unauthorized. A callback that scopes credentials to the original trusted URL can therefore return GIT_CREDENTIAL_USERPASS_PLAINTEXT credentials that libgit2 stores in transport->server.cred and sends as an Authorization header to the redirected host. An attacker who controls a trusted Git host or an open redirect on that host can disclose HTTP Basic credentials, personal access tokens, or equivalent credentials. This issue is fixed in versions 1.8.6 and 1.9.5.","publishedAt":"2026-08-20T19:16:54","lastModifiedAt":"2026-08-21T22:16:39","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-53586","cvssScore":6.5,"cvssVector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N","epssProbability":0.00276,"riskScore":0.67,"affectedProduct":"libgit2","affectedVersions":"<1.8.6, <1.9.5","vulnerabilityType":"Library","operatingSystems":[],"links":{"self":"https://www.redsauce.net/api/cves/CVE-2026-53586","webPages":{"es":"https://www.redsauce.net/es/cves/CVE-2026-53586","en":"https://www.redsauce.net/en/cves/CVE-2026-53586","fr":"https://www.redsauce.net/fr/cves/CVE-2026-53586","pt":"https://www.redsauce.net/pt/cves/CVE-2026-53586","de":"https://www.redsauce.net/de/cves/CVE-2026-53586","sk":"https://www.redsauce.net/sk/cves/CVE-2026-53586","el":"https://www.redsauce.net/el/cves/CVE-2026-53586"},"source":"https://nvd.nist.gov/vuln/detail/CVE-2026-53586"}}